/**
 * @file
 * Sockets BSD-Like API module
 *
 */

/*
 * Copyright (c) 2001-2004 Swedish Institute of Computer Science.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without modification,
 * are permitted provided that the following conditions are met:
 *
 * 1. Redistributions of source code must retain the above copyright notice,
 *    this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright notice,
 *    this list of conditions and the following disclaimer in the documentation
 *    and/or other materials provided with the distribution.
 * 3. The name of the author may not be used to endorse or promote products
 *    derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
 * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
 * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
 * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
 * OF SUCH DAMAGE.
 *
 * This file is part of the lwIP TCP/IP stack.
 *
 * Author: Adam Dunkels <adam@sics.se>
 *
 * Improved by Marc Boucher <marc@mbsi.ca> and David Haas <dhaas@alum.rpi.edu>
 *
 */

#include "lwip/opt.h"

#if LWIP_SOCKET /* don't build if not configured for use in lwipopts.h */

#include "lwip/sockets.h"
#include "lwip/api.h"
#include "lwip/sys.h"
#include "lwip/igmp.h"
#include "lwip/inet.h"
#include "lwip/tcp.h"
#include "lwip/raw.h"
#include "lwip/udp.h"
#include "lwip/tcpip.h"

#include <string.h>

#define NUM_SOCKETS MEMP_NUM_NETCONN

/** Contains all internal pointers and states used for a socket */
struct lwip_socket
{
    /** sockets currently are built on netconns, each socket has one netconn */
    struct netconn *conn;
    /** data that was left from the previous read */
    struct netbuf *lastdata;
    /** offset in the data that was left from the previous read */
    u16_t lastoffset;
    /** number of times data was received, set by event_callback(),
        tested by the receive and select functions */
    s16_t rcvevent;
    /** number of times data was received, set by event_callback(),
        tested by select */
    u16_t sendevent;
    /** socket flags (currently, only used for O_NONBLOCK) */
    u16_t flags;
    /** last error that occurred on this socket */
    int err;
};

/** Description for a task waiting in select */
struct lwip_select_cb
{
    /** Pointer to the next waiting task */
    struct lwip_select_cb *next;
    /** readset passed to select */
    fd_set *readset;
    /** writeset passed to select */
    fd_set *writeset;
    /** unimplemented: exceptset passed to select */
    fd_set *exceptset;
    /** don't signal the same semaphore twice: set to 1 when signalled */
    int sem_signalled;
    /** semaphore to wake up a task waiting for select */
    sys_sem_t sem;
};

/** This struct is used to pass data to the set/getsockopt_internal
 * functions running in tcpip_thread context (only a void* is allowed) */
struct lwip_setgetsockopt_data
{
    /** socket struct for which to change options */
    struct lwip_socket *sock;
    /** socket index for which to change options */
    int s;
    /** level of the option to process */
    int level;
    /** name of the option to process */
    int optname;
    /** set: value to set the option to
     * get: value of the option is stored here */
    void *optval;
    /** size of *optval */
    socklen_t *optlen;
    /** if an error occures, it is temporarily stored here */
    err_t err;
};

/** The global array of available sockets */
static struct lwip_socket sockets[NUM_SOCKETS];
/** The global list of tasks waiting for select */
static struct lwip_select_cb *select_cb_list;

/** Semaphore protecting the sockets array */
static sys_sem_t socksem;
/** Semaphore protecting select_cb_list */
static sys_sem_t selectsem;

/** Table to quickly map an lwIP error (err_t) to a socket error
 * by using -err as an index */
static const int err_to_errno_table[] = {
    0,            /* ERR_OK          0      No error, everything OK. */
    ENOMEM,       /* ERR_MEM        -1      Out of memory error.     */
    ENOBUFS,      /* ERR_BUF        -2      Buffer error.            */
    ETIMEDOUT,    /* ERR_TIMEOUT    -3      Timeout                  */
    EHOSTUNREACH, /* ERR_RTE        -4      Routing problem.         */
    ECONNABORTED, /* ERR_ABRT       -5      Connection aborted.      */
    ECONNRESET,   /* ERR_RST        -6      Connection reset.        */
    ESHUTDOWN,    /* ERR_CLSD       -7      Connection closed.       */
    ENOTCONN,     /* ERR_CONN       -8      Not connected.           */
    EINVAL,       /* ERR_VAL        -9      Illegal value.           */
    EIO,          /* ERR_ARG        -10     Illegal argument.        */
    EADDRINUSE,   /* ERR_USE        -11     Address in use.          */
    -1,           /* ERR_IF         -12     Low-level netif error    */
    -1,           /* ERR_ISCONN     -13     Already connected.       */
    EINPROGRESS   /* ERR_INPROGRESS -14     Operation in progress    */
};

#define ERR_TO_ERRNO_TABLE_SIZE \
    (sizeof(err_to_errno_table) / sizeof(err_to_errno_table[0]))

#define err_to_errno(err) \
    ((unsigned)(-(err)) < ERR_TO_ERRNO_TABLE_SIZE ? \
     err_to_errno_table[-(err)] : EIO)

#ifdef ERRNO
#ifndef set_errno
#define set_errno(err) errno = (err)
#endif
#else
#define set_errno(err)
#endif

#define sock_set_errno(sk, e) do { \
        sk->err = (e); \
        set_errno(sk->err); \
} while (0)

/* Forward delcaration of some functions */
static void event_callback(struct netconn *conn, enum netconn_evt evt, u16_t len);
static void lwip_getsockopt_internal(void *arg);
static void lwip_setsockopt_internal(void *arg);

/**
 * Initialize this module. This function has to be called before any other
 * functions in this module!
 */
void
lwip_socket_init(void)
{
    socksem   = sys_sem_new(1);
    selectsem = sys_sem_new(1);
}

/**
 * Map a externally used socket index to the internal socket representation.
 *
 * @param s externally used socket index
 * @return struct lwip_socket for the socket or NULL if not found
 */
static struct lwip_socket *
get_socket(int s)
{
    struct lwip_socket *sock;

    if ((s < 0) || (s >= NUM_SOCKETS))
    {
        LWIP_DEBUGF(SOCKETS_DEBUG, ("get_socket(%d): invalid\n", s));
        set_errno(EBADF);
        return NULL;
    }

    sock = &sockets[s];

    if (!sock->conn)
    {
        LWIP_DEBUGF(SOCKETS_DEBUG, ("get_socket(%d): not active\n", s));
        set_errno(EBADF);
        return NULL;
    }

    return sock;
}

/**
 * Allocate a new socket for a given netconn.
 *
 * @param newconn the netconn for which to allocate a socket
 * @return the index of the new socket; -1 on error
 */
static int
alloc_socket(struct netconn *newconn)
{
    int i;

    /* Protect socket array */
    sys_sem_wait(socksem);

    /* allocate a new socket identifier */
    for (i = 0; i < NUM_SOCKETS; ++i)
    {
        if (!sockets[i].conn)
        {
            sockets[i].conn       = newconn;
            sockets[i].lastdata   = NULL;
            sockets[i].lastoffset = 0;
            sockets[i].rcvevent   = 0;
            sockets[i].sendevent  = 1; /* TCP send buf is empty */
            sockets[i].flags      = 0;
            sockets[i].err        = 0;
            sys_sem_signal(socksem);
            return i;
        }
    }
    sys_sem_signal(socksem);
    return -1;
}

/* Below this, the well-known socket functions are implemented.
 * Use google.com or opengroup.org to get a good description :-)
 *
 * Exceptions are documented!
 */

int
lwip_accept(int s, struct sockaddr *addr, socklen_t *addrlen)
{
    struct lwip_socket *sock, *nsock;
    struct netconn *newconn;
    struct ip_addr naddr;
    u16_t port;
    int newsock;
    struct sockaddr_in sin;
    err_t err;

    LWIP_DEBUGF(SOCKETS_DEBUG, ("lwip_accept(%d)...\n", s));
    sock = get_socket(s);
    if (!sock)
    {
        return -1;
    }

    if ((sock->flags & O_NONBLOCK) && (sock->rcvevent <= 0))
    {
        LWIP_DEBUGF(SOCKETS_DEBUG, ("lwip_accept(%d): returning EWOULDBLOCK\n", s));
        sock_set_errno(sock, EWOULDBLOCK);
        return -1;
    }

    newconn = netconn_accept(sock->conn);
    if (!newconn)
    {
        LWIP_DEBUGF(SOCKETS_DEBUG, ("lwip_accept(%d) failed, err=%d\n", s, sock->conn->err));
        sock_set_errno(sock, err_to_errno(sock->conn->err));
        return -1;
    }

    /* get the IP address and port of the remote host */
    err = netconn_peer(newconn, &naddr, &port);
    if (err != ERR_OK)
    {
        netconn_delete(newconn);
        sock_set_errno(sock, err_to_errno(err));
        return -1;
    }

    /* Note that POSIX only requires us to check addr is non-NULL. addrlen must
     * not be NULL if addr is valid.
     */
    if (NULL != addr)
    {
        LWIP_ASSERT("addr valid but addrlen NULL", addrlen != NULL);
        memset(&sin, 0, sizeof(sin));
        sin.sin_len = sizeof(sin);
        sin.sin_family = AF_INET;
        sin.sin_port = htons(port);
        sin.sin_addr.s_addr = naddr.addr;

        if (*addrlen > sizeof(sin))
        {
            *addrlen = sizeof(sin);
        }

        MEMCPY(addr, &sin, *addrlen);
    }

    newsock = alloc_socket(newconn);
    if (newsock == -1)
    {
        netconn_delete(newconn);
        sock_set_errno(sock, ENFILE);
        return -1;
    }
    LWIP_ASSERT("invalid socket index", (newsock >= 0) && (newsock < NUM_SOCKETS));
    newconn->callback = event_callback;
    nsock = &sockets[newsock];
    LWIP_ASSERT("invalid socket pointer", nsock != NULL);

    sys_sem_wait(socksem);
    /* See event_callback: If data comes in right away after an accept, even
     * though the server task might not have created a new socket yet.
     * In that case, newconn->socket is counted down (newconn->socket--),
     * so nsock->rcvevent is >= 1 here!
     */
    nsock->rcvevent += -1 - newconn->socket;
    newconn->socket = newsock;
    sys_sem_signal(socksem);

    LWIP_DEBUGF(SOCKETS_DEBUG, ("lwip_accept(%d) returning new sock=%d addr=", s, newsock));
    ip_addr_debug_print(SOCKETS_DEBUG, &naddr);
    LWIP_DEBUGF(SOCKETS_DEBUG, (" port=%"U 16_F "\n", port));

    sock_set_errno(sock, 0);
    return newsock;
}

int
lwip_bind(int s, const struct sockaddr *name, socklen_t namelen)
{
    struct lwip_socket *sock;
    struct ip_addr local_addr;
    u16_t local_port;
    err_t err;

    sock = get_socket(s);
    if (!sock)
    {
        return -1;
    }

    LWIP_ERROR("lwip_bind: invalid address", ((namelen == sizeof(struct sockaddr_in)) &&
                                              ((((const struct sockaddr_in*)name)->sin_family) == AF_INET)),
               sock_set_errno(sock, err_to_errno(ERR_ARG)); return -1; );

    local_addr.addr = ((const struct sockaddr_in*)name)->sin_addr.s_addr;
    local_port = ((const struct sockaddr_in*)name)->sin_port;

    LWIP_DEBUGF(SOCKETS_DEBUG, ("lwip_bind(%d, addr=", s));
    ip_addr_debug_print(SOCKETS_DEBUG, &local_addr);
    LWIP_DEBUGF(SOCKETS_DEBUG, (" port=%"U 16_F ")\n", ntohs(local_port)));

    err = netconn_bind(sock->conn, &local_addr, ntohs(local_port));

    if (err != ERR_OK)
    {
        LWIP_DEBUGF(SOCKETS_DEBUG, ("lwip_bind(%d) failed, err=%d\n", s, err));
        sock_set_errno(sock, err_to_errno(err));
        return -1;
    }

    LWIP_DEBUGF(SOCKETS_DEBUG, ("lwip_bind(%d) succeeded\n", s));
    sock_set_errno(sock, 0);
    return 0;
}

int
lwip_close(int s)
{
    struct lwip_socket *sock;

    LWIP_DEBUGF(SOCKETS_DEBUG, ("lwip_close(%d)\n", s));

    sock = get_socket(s);
    if (!sock)
    {
        return -1;
    }

    netconn_delete(sock->conn);

    sys_sem_wait(socksem);
    if (sock->lastdata)
    {
        netbuf_delete(sock->lastdata);
    }
    sock->lastdata   = NULL;
    sock->lastoffset = 0;
    sock->conn       = NULL;
    sock_set_errno(sock, 0);
    sys_sem_signal(socksem);
    return 0;
}

int
lwip_connect(int s, const struct sockaddr *name, socklen_t namelen)
{
    struct lwip_socket *sock;
    err_t err;

    sock = get_socket(s);
    if (!sock)
    {
        return -1;
    }

    LWIP_ERROR("lwip_connect: invalid address", ((namelen == sizeof(struct sockaddr_in)) &&
                                                 ((((const struct sockaddr_in*)name)->sin_family) == AF_INET)),
               sock_set_errno(sock, err_to_errno(ERR_ARG)); return -1; );

    if (((const struct sockaddr_in*)name)->sin_family == AF_UNSPEC)
    {
        LWIP_DEBUGF(SOCKETS_DEBUG, ("lwip_connect(%d, AF_UNSPEC)\n", s));
        err = netconn_disconnect(sock->conn);
    }
    else
    {
        struct ip_addr remote_addr;
        u16_t remote_port;

        remote_addr.addr = ((const struct sockaddr_in*)name)->sin_addr.s_addr;
        remote_port = ((const struct sockaddr_in*)name)->sin_port;

        LWIP_DEBUGF(SOCKETS_DEBUG, ("lwip_connect(%d, addr=", s));
        ip_addr_debug_print(SOCKETS_DEBUG, &remote_addr);
        LWIP_DEBUGF(SOCKETS_DEBUG, (" port=%"U 16_F ")\n", ntohs(remote_port)));

        err = netconn_connect(sock->conn, &remote_addr, ntohs(remote_port));
    }

    if (err != ERR_OK)
    {
        LWIP_DEBUGF(SOCKETS_DEBUG, ("lwip_connect(%d) failed, err=%d\n", s, err));
        sock_set_errno(sock, err_to_errno(err));
        return -1;
    }

    LWIP_DEBUGF(SOCKETS_DEBUG, ("lwip_connect(%d) succeeded\n", s));
    sock_set_errno(sock, 0);
    return 0;
}

/**
 * Set a socket into listen mode.
 * The socket may not have been used for another connection previously.
 *
 * @param s the socket to set to listening mode
 * @param backlog (ATTENTION: need TCP_LISTEN_BACKLOG=1)
 * @return 0 on success, non-zero on failure
 */
int
lwip_listen(int s, int backlog)
{
    struct lwip_socket *sock;
    err_t err;

    LWIP_DEBUGF(SOCKETS_DEBUG, ("lwip_listen(%d, backlog=%d)\n", s, backlog));

    sock = get_socket(s);
    if (!sock)
    {
        return -1;
    }

    /* limit the "backlog" parameter to fit in an u8_t */
    if (backlog < 0)
    {
        backlog = 0;
    }
    if (backlog > 0xff)
    {
        backlog = 0xff;
    }

    err = netconn_listen_with_backlog(sock->conn, backlog);

    if (err != ERR_OK)
    {
        LWIP_DEBUGF(SOCKETS_DEBUG, ("lwip_listen(%d) failed, err=%d\n", s, err));
        sock_set_errno(sock, err_to_errno(err));
        return -1;
    }

    sock_set_errno(sock, 0);
    return 0;
}

int
lwip_recvfrom(int s, void *mem, size_t len, int flags,
              struct sockaddr *from, socklen_t *fromlen)
{
    struct lwip_socket *sock;
    struct netbuf      *buf;
    u16_t buflen, copylen, off = 0;
    struct ip_addr     *addr;
    u16_t port;
    u8_t done = 0;

    LWIP_DEBUGF(SOCKETS_DEBUG, ("lwip_recvfrom(%d, %p, %"SZT_F ", 0x%x, ..)\n", s, mem, len, flags));
    sock = get_socket(s);
    if (!sock)
    {
        return -1;
    }

    do
    {
        LWIP_DEBUGF(SOCKETS_DEBUG, ("lwip_recvfrom: top while sock->lastdata=%p\n", (void*)sock->lastdata));
        /* Check if there is data left from the last recv operation. */
        if (sock->lastdata)
        {
            buf = sock->lastdata;
        }
        else
        {
            /* If this is non-blocking call, then check first */
            if (((flags & MSG_DONTWAIT) || (sock->flags & O_NONBLOCK)) &&
                (sock->rcvevent <= 0))
            {
                if (off > 0)
                {
                    /* already received data, return that */
                    sock_set_errno(sock, 0);
                    return off;
                }
                LWIP_DEBUGF(SOCKETS_DEBUG, ("lwip_recvfrom(%d): returning EWOULDBLOCK\n", s));
                sock_set_errno(sock, EWOULDBLOCK);
                return -1;
            }

            /* No data was left from the previous operation, so we try to get
               some from the network. */
            sock->lastdata = buf = netconn_recv(sock->conn);
            LWIP_DEBUGF(SOCKETS_DEBUG, ("lwip_recvfrom: netconn_recv netbuf=%p\n", (void*)buf));

            if (!buf)
            {
                if (off > 0)
                {
                    /* already received data, return that */
                    sock_set_errno(sock, 0);
                    return off;
                }
                /* We should really do some error checking here. */
                LWIP_DEBUGF(SOCKETS_DEBUG, ("lwip_recvfrom(%d): buf == NULL!\n", s));
                sock_set_errno(sock, (((sock->conn->pcb.ip != NULL) && (sock->conn->err == ERR_OK))
                                      ? ETIMEDOUT : err_to_errno(sock->conn->err)));
                return 0;
            }
        }

        buflen = netbuf_len(buf);
        LWIP_DEBUGF(SOCKETS_DEBUG, ("lwip_recvfrom: buflen=%"U 16_F " len=%"SZT_F " off=%"U 16_F " sock->lastoffset=%"U 16_F "\n",
                                    buflen, len, off, sock->lastoffset));

        buflen -= sock->lastoffset;

        if (len > buflen)
        {
            copylen = buflen;
        }
        else
        {
            copylen = (u16_t)len;
        }

        /* copy the contents of the received buffer into
           the supplied memory pointer mem */
        netbuf_copy_partial(buf, (u8_t*)mem + off, copylen, sock->lastoffset);

        off += copylen;

        if (netconn_type(sock->conn) == NETCONN_TCP)
        {
            LWIP_ASSERT("invalid copylen, len would underflow", len >= copylen);
            len -= copylen;
            if ( (len <= 0) ||
                 (buf->p->flags & PBUF_FLAG_PUSH) ||
                 (sock->rcvevent <= 0) ||
                 ((flags & MSG_PEEK) != 0))
            {
                done = 1;
            }
        }
        else
        {
            done = 1;
        }

        /* Check to see from where the data was.*/
        if (done)
        {
            if (from && fromlen)
            {
                struct sockaddr_in sin;

                if (netconn_type(sock->conn) == NETCONN_TCP)
                {
                    addr = (struct ip_addr*)&(sin.sin_addr.s_addr);
                    netconn_getaddr(sock->conn, addr, &port, 0);
                }
                else
                {
                    addr = netbuf_fromaddr(buf);
                    port = netbuf_fromport(buf);
                }

                memset(&sin, 0, sizeof(sin));
                sin.sin_len = sizeof(sin);
                sin.sin_family = AF_INET;
                sin.sin_port = htons(port);
                sin.sin_addr.s_addr = addr->addr;

                if (*fromlen > sizeof(sin))
                {
                    *fromlen = sizeof(sin);
                }

                MEMCPY(from, &sin, *fromlen);

                LWIP_DEBUGF(SOCKETS_DEBUG, ("lwip_recvfrom(%d): addr=", s));
                ip_addr_debug_print(SOCKETS_DEBUG, addr);
                LWIP_DEBUGF(SOCKETS_DEBUG, (" port=%"U 16_F " len=%"U 16_F "\n", port, off));
            }
            else
            {
  #if SOCKETS_DEBUG
                struct sockaddr_in sin;

                if (netconn_type(sock->conn) == NETCONN_TCP)
                {
                    addr = (struct ip_addr*)&(sin.sin_addr.s_addr);
                    netconn_getaddr(sock->conn, addr, &port, 0);
                }
                else
                {
                    addr = netbuf_fromaddr(buf);
                    port = netbuf_fromport(buf);
                }

                LWIP_DEBUGF(SOCKETS_DEBUG, ("lwip_recvfrom(%d): addr=", s));
                ip_addr_debug_print(SOCKETS_DEBUG, addr);
                LWIP_DEBUGF(SOCKETS_DEBUG, (" port=%"U 16_F " len=%"U 16_F "\n", port, off));
  #endif        /*  SOCKETS_DEBUG */
            }
        }

        /* If we don't peek the incoming message... */
        if ((flags & MSG_PEEK) == 0)
        {
            /* If this is a TCP socket, check if there is data left in the
               buffer. If so, it should be saved in the sock structure for next
               time around. */
            if ((netconn_type(sock->conn) == NETCONN_TCP) && (buflen - copylen > 0))
            {
                sock->lastdata = buf;
                sock->lastoffset += copylen;
                LWIP_DEBUGF(SOCKETS_DEBUG, ("lwip_recvfrom: lastdata now netbuf=%p\n", (void*)buf));
            }
            else
            {
                sock->lastdata = NULL;
                sock->lastoffset = 0;
                LWIP_DEBUGF(SOCKETS_DEBUG, ("lwip_recvfrom: deleting netbuf=%p\n", (void*)buf));
                netbuf_delete(buf);
            }
        }
    }
    while (!done);

    sock_set_errno(sock, 0);
    return off;
}

int
lwip_read(int s, void *mem, size_t len)
{
    return lwip_recvfrom(s, mem, len, 0, NULL, NULL);
}

int
lwip_recv(int s, void *mem, size_t len, int flags)
{
    return lwip_recvfrom(s, mem, len, flags, NULL, NULL);
}

int
lwip_send(int s, const void *data, size_t size, int flags)
{
    struct lwip_socket *sock;
    err_t err;

    LWIP_DEBUGF(SOCKETS_DEBUG, ("lwip_send(%d, data=%p, size=%"SZT_F ", flags=0x%x)\n",
                                s, data, size, flags));

    sock = get_socket(s);
    if (!sock)
    {
        return -1;
    }

    if (sock->conn->type != NETCONN_TCP)
    {
#if (LWIP_UDP || LWIP_RAW)
        return lwip_sendto(s, data, size, flags, NULL, 0);
#else
        sock_set_errno(sock, err_to_errno(ERR_ARG));
        return -1;
#endif  /* (LWIP_UDP || LWIP_RAW) */
    }

    err = netconn_write(sock->conn, data, size, NETCONN_COPY | ((flags & MSG_MORE) ? NETCONN_MORE : 0));

    LWIP_DEBUGF(SOCKETS_DEBUG, ("lwip_send(%d) err=%d size=%"SZT_F "\n", s, err, size));
    sock_set_errno(sock, err_to_errno(err));
    return err == ERR_OK ? (int)size : -1;
}

int
lwip_sendto(int s, const void *data, size_t size, int flags,
            const struct sockaddr *to, socklen_t tolen)
{
    struct lwip_socket *sock;
    struct ip_addr remote_addr;
    err_t err;
    u16_t short_size;

#if !LWIP_TCPIP_CORE_LOCKING
    struct netbuf buf;
    u16_t remote_port;
#endif

    sock = get_socket(s);
    if (!sock)
    {
        return -1;
    }

    if (sock->conn->type == NETCONN_TCP)
    {
#if LWIP_TCP
        return lwip_send(s, data, size, flags);
#else
        sock_set_errno(sock, err_to_errno(ERR_ARG));
        return -1;
#endif  /* LWIP_TCP */
    }

    LWIP_ASSERT("lwip_sendto: size must fit in u16_t", size <= 0xffff);
    short_size = (u16_t)size;
    LWIP_ERROR("lwip_sendto: invalid address", (((to == NULL) && (tolen == 0)) ||
                                                ((tolen == sizeof(struct sockaddr_in)) &&
                                                 ((((const struct sockaddr_in*)to)->sin_family) == AF_INET))),
               sock_set_errno(sock, err_to_errno(ERR_ARG)); return -1; );

#if LWIP_TCPIP_CORE_LOCKING
    /* Should only be consider like a sample or a simple way to experiment this option (no check of "to" field...) */
    { struct pbuf* p;

      p = pbuf_alloc(PBUF_TRANSPORT, 0, PBUF_REF);
      if (p == NULL)
      {
          err = ERR_MEM;
      }
      else
      {
          p->payload = (void*)data;
          p->len = p->tot_len = short_size;

          remote_addr.addr = ((const struct sockaddr_in*)to)->sin_addr.s_addr;

          LOCK_TCPIP_CORE();
          if (sock->conn->type == NETCONN_RAW)
          {
              err = sock->conn->err = raw_sendto(sock->conn->pcb.raw, p, &remote_addr);
          }
          else
          {
              err = sock->conn->err = udp_sendto(sock->conn->pcb.udp, p, &remote_addr, ntohs(((const struct sockaddr_in*)to)->sin_port));
          }
          UNLOCK_TCPIP_CORE();

          pbuf_free(p);
      } }
#else
    /* initialize a buffer */
    buf.p = buf.ptr = NULL;
    if (to)
    {
        remote_addr.addr = ((const struct sockaddr_in*)to)->sin_addr.s_addr;
        remote_port      = ntohs(((const struct sockaddr_in*)to)->sin_port);
        buf.addr         = &remote_addr;
        buf.port         = remote_port;
    }
    else
    {
        remote_addr.addr = 0;
        remote_port      = 0;
        buf.addr         = NULL;
        buf.port         = 0;
    }

    LWIP_DEBUGF(SOCKETS_DEBUG, ("lwip_sendto(%d, data=%p, short_size=%d"U 16_F ", flags=0x%x to=",
                                s, data, short_size, flags));
    ip_addr_debug_print(SOCKETS_DEBUG, &remote_addr);
    LWIP_DEBUGF(SOCKETS_DEBUG, (" port=%"U 16_F "\n", remote_port));

    /* make the buffer point to the data that should be sent */
#if LWIP_NETIF_TX_SINGLE_PBUF
    /* Allocate a new netbuf and copy the data into it. */
    if (netbuf_alloc(&buf, short_size) == NULL)
    {
        err = ERR_MEM;
    }
    else
    {
        err = netbuf_take(&buf, data, short_size);
    }
#else /* LWIP_NETIF_TX_SINGLE_PBUF */
    err = netbuf_ref(&buf, data, short_size);
#endif /* LWIP_NETIF_TX_SINGLE_PBUF */
    if (err == ERR_OK)
    {
        /* send the data */
        err = netconn_send(sock->conn, &buf);
    }

    /* deallocated the buffer */
    netbuf_free(&buf);
#endif /* LWIP_TCPIP_CORE_LOCKING */
    sock_set_errno(sock, err_to_errno(err));
    return err == ERR_OK ? short_size : -1;
}

int
lwip_socket(int domain, int type, int protocol)
{
    struct netconn *conn;
    int i;

    LWIP_UNUSED_ARG(domain);

    /* create a netconn */
    switch (type)
    {
    case SOCK_RAW:
        conn = netconn_new_with_proto_and_callback(NETCONN_RAW, (u8_t)protocol, event_callback);
        LWIP_DEBUGF(SOCKETS_DEBUG, ("lwip_socket(%s, SOCK_RAW, %d) = ",
                                    domain == PF_INET ? "PF_INET" : "UNKNOWN", protocol));
        break;
    case SOCK_DGRAM:
        conn = netconn_new_with_callback( (protocol == IPPROTO_UDPLITE) ?
                                          NETCONN_UDPLITE : NETCONN_UDP, event_callback);
        LWIP_DEBUGF(SOCKETS_DEBUG, ("lwip_socket(%s, SOCK_DGRAM, %d) = ",
                                    domain == PF_INET ? "PF_INET" : "UNKNOWN", protocol));
        break;
    case SOCK_STREAM:
        conn = netconn_new_with_callback(NETCONN_TCP, event_callback);
        LWIP_DEBUGF(SOCKETS_DEBUG, ("lwip_socket(%s, SOCK_STREAM, %d) = ",
                                    domain == PF_INET ? "PF_INET" : "UNKNOWN", protocol));
        break;
    default:
        LWIP_DEBUGF(SOCKETS_DEBUG, ("lwip_socket(%d, %d/UNKNOWN, %d) = -1\n",
                                    domain, type, protocol));
        set_errno(EINVAL);
        return -1;
    }

    if (!conn)
    {
        LWIP_DEBUGF(SOCKETS_DEBUG, ("-1 / ENOBUFS (could not create netconn)\n"));
        set_errno(ENOBUFS);
        return -1;
    }

    i = alloc_socket(conn);

    if (i == -1)
    {
        netconn_delete(conn);
        set_errno(ENFILE);
        return -1;
    }
    conn->socket = i;
    LWIP_DEBUGF(SOCKETS_DEBUG, ("%d\n", i));
    set_errno(0);
    return i;
}

int
lwip_write(int s, const void *data, size_t size)
{
    return lwip_send(s, data, size, 0);
}

/**
 * Go through the readset and writeset lists and see which socket of the sockets
 * set in the sets has events. On return, readset, writeset and exceptset have
 * the sockets enabled that had events.
 *
 * exceptset is not used for now!!!
 *
 * @param maxfdp1 the highest socket index in the sets
 * @param readset in: set of sockets to check for read events;
 *                out: set of sockets that had read events
 * @param writeset in: set of sockets to check for write events;
 *                 out: set of sockets that had write events
 * @param exceptset not yet implemented
 * @return number of sockets that had events (read+write)
 */
static int
lwip_selscan(int maxfdp1, fd_set *readset, fd_set *writeset, fd_set *exceptset)
{
    int i, nready = 0;
    fd_set lreadset, lwriteset, lexceptset;
    struct lwip_socket *p_sock;

    FD_ZERO(&lreadset);
    FD_ZERO(&lwriteset);
    FD_ZERO(&lexceptset);

    /* Go through each socket in each list to count number of sockets which
       currently match */
    for (i = 0; i < maxfdp1; i++)
    {
        if (FD_ISSET(i, readset))
        {
            /* See if netconn of this socket is ready for read */
            p_sock = get_socket(i);
            if (p_sock && (p_sock->lastdata || (p_sock->rcvevent > 0)))
            {
                FD_SET(i, &lreadset);
                LWIP_DEBUGF(SOCKETS_DEBUG, ("lwip_selscan: fd=%d ready for reading\n", i));
                nready++;
            }
        }
        if (FD_ISSET(i, writeset))
        {
            /* See if netconn of this socket is ready for write */
            p_sock = get_socket(i);
            if (p_sock && p_sock->sendevent)
            {
                FD_SET(i, &lwriteset);
                LWIP_DEBUGF(SOCKETS_DEBUG, ("lwip_selscan: fd=%d ready for writing\n", i));
                nready++;
            }
        }
    }
    *readset = lreadset;
    *writeset = lwriteset;
    FD_ZERO(exceptset);

    return nready;
}


/**
 * Processing exceptset is not yet implemented.
 */
int
lwip_select(int maxfdp1, fd_set *readset, fd_set *writeset, fd_set *exceptset,
            struct timeval *timeout)
{
    int i;
    int nready;
    fd_set lreadset, lwriteset, lexceptset;
    u32_t msectimeout;
    struct lwip_select_cb select_cb;
    struct lwip_select_cb *p_selcb;

    LWIP_DEBUGF(SOCKETS_DEBUG, ("lwip_select(%d, %p, %p, %p, tvsec=%ld tvusec=%ld)\n",
                                maxfdp1, (void*)readset, (void*)writeset, (void*)exceptset,
                                timeout ? (long)timeout->tv_sec : (long)-1,
                                timeout ? (long)timeout->tv_usec : (long)-1));

    select_cb.next = 0;
    select_cb.readset = readset;
    select_cb.writeset = writeset;
    select_cb.exceptset = exceptset;
    select_cb.sem_signalled = 0;

    /* Protect ourselves searching through the list */
    sys_sem_wait(selectsem);

    if (readset)
    {
        lreadset = *readset;
    }
    else
    {
        FD_ZERO(&lreadset);
    }
    if (writeset)
    {
        lwriteset = *writeset;
    }
    else
    {
        FD_ZERO(&lwriteset);
    }
    if (exceptset)
    {
        lexceptset = *exceptset;
    }
    else
    {
        FD_ZERO(&lexceptset);
    }

    /* Go through each socket in each list to count number of sockets which
       currently match */
    nready = lwip_selscan(maxfdp1, &lreadset, &lwriteset, &lexceptset);

    /* If we don't have any current events, then suspend if we are supposed to */
    if (!nready)
    {
        if (timeout && timeout->tv_sec == 0 && timeout->tv_usec == 0)
        {
            sys_sem_signal(selectsem);
            if (readset)
            {
                FD_ZERO(readset);
            }
            if (writeset)
            {
                FD_ZERO(writeset);
            }
            if (exceptset)
            {
                FD_ZERO(exceptset);
            }

            LWIP_DEBUGF(SOCKETS_DEBUG, ("lwip_select: no timeout, returning 0\n"));
            set_errno(0);

            return 0;
        }

        /* add our semaphore to list */
        /* We don't actually need any dynamic memory. Our entry on the
         * list is only valid while we are in this function, so it's ok
         * to use local variables */

        select_cb.sem = sys_sem_new(0);
        /* Note that we are still protected */
        /* Put this select_cb on top of list */
        select_cb.next = select_cb_list;
        select_cb_list = &select_cb;

        /* Now we can safely unprotect */
        sys_sem_signal(selectsem);

        /* Now just wait to be woken */
        if (timeout == 0)
        {
            /* Wait forever */
            msectimeout = 0;
        }
        else
        {
            msectimeout =  ((timeout->tv_sec * 1000) + ((timeout->tv_usec + 500) / 1000));
            if (msectimeout == 0)
            {
                msectimeout = 1;
            }
        }

        i = sys_sem_wait_timeout(select_cb.sem, msectimeout);

        /* Take us off the list */
        sys_sem_wait(selectsem);
        if (select_cb_list == &select_cb)
        {
            select_cb_list = select_cb.next;
        }
        else
        {
            for (p_selcb = select_cb_list; p_selcb; p_selcb = p_selcb->next)
            {
                if (p_selcb->next == &select_cb)
                {
                    p_selcb->next = select_cb.next;
                    break;
                }
            }
        }

        sys_sem_signal(selectsem);

        sys_sem_free(select_cb.sem);
        if (i == 0)
        {
            /* Timeout */
            if (readset)
            {
                FD_ZERO(readset);
            }
            if (writeset)
            {
                FD_ZERO(writeset);
            }
            if (exceptset)
            {
                FD_ZERO(exceptset);
            }

            LWIP_DEBUGF(SOCKETS_DEBUG, ("lwip_select: timeout expired\n"));
            set_errno(0);

            return 0;
        }

        if (readset)
        {
            lreadset = *readset;
        }
        else
        {
            FD_ZERO(&lreadset);
        }
        if (writeset)
        {
            lwriteset = *writeset;
        }
        else
        {
            FD_ZERO(&lwriteset);
        }
        if (exceptset)
        {
            lexceptset = *exceptset;
        }
        else
        {
            FD_ZERO(&lexceptset);
        }

        /* See what's set */
        nready = lwip_selscan(maxfdp1, &lreadset, &lwriteset, &lexceptset);
    }
    else
    {
        sys_sem_signal(selectsem);
    }

    if (readset)
    {
        *readset = lreadset;
    }
    if (writeset)
    {
        *writeset = lwriteset;
    }
    if (exceptset)
    {
        *exceptset = lexceptset;
    }

    LWIP_DEBUGF(SOCKETS_DEBUG, ("lwip_select: nready=%d\n", nready));
    set_errno(0);

    return nready;
}

/**
 * Callback registered in the netconn layer for each socket-netconn.
 * Processes recvevent (data available) and wakes up tasks waiting for select.
 */
static void
event_callback(struct netconn *conn, enum netconn_evt evt, u16_t len)
{
    int s;
    struct lwip_socket *sock;
    struct lwip_select_cb *scb;

    LWIP_UNUSED_ARG(len);

    /* Get socket */
    if (conn)
    {
        s = conn->socket;
        if (s < 0)
        {
            /* Data comes in right away after an accept, even though
             * the server task might not have created a new socket yet.
             * Just count down (or up) if that's the case and we
             * will use the data later. Note that only receive events
             * can happen before the new socket is set up. */
            sys_sem_wait(socksem);
            if (conn->socket < 0)
            {
                if (evt == NETCONN_EVT_RCVPLUS)
                {
                    conn->socket--;
                }
                sys_sem_signal(socksem);
                return;
            }
            s = conn->socket;
            sys_sem_signal(socksem);
        }

        sock = get_socket(s);
        if (!sock)
        {
            return;
        }
    }
    else
    {
        return;
    }

    sys_sem_wait(selectsem);
    /* Set event as required */
    switch (evt)
    {
    case NETCONN_EVT_RCVPLUS:
        sock->rcvevent++;
        break;
    case NETCONN_EVT_RCVMINUS:
        sock->rcvevent--;
        break;
    case NETCONN_EVT_SENDPLUS:
        sock->sendevent = 1;
        break;
    case NETCONN_EVT_SENDMINUS:
        sock->sendevent = 0;
        break;
    default:
        LWIP_ASSERT("unknown event", 0);
        break;
    }
    sys_sem_signal(selectsem);

    /* Now decide if anyone is waiting for this socket */
    /* NOTE: This code is written this way to protect the select link list
       but to avoid a deadlock situation by releasing socksem before
       signalling for the select. This means we need to go through the list
       multiple times ONLY IF a select was actually waiting. We go through
       the list the number of waiting select calls + 1. This list is
       expected to be small. */
    while (1)
    {
        sys_sem_wait(selectsem);
        for (scb = select_cb_list; scb; scb = scb->next)
        {
            if (scb->sem_signalled == 0)
            {
                /* Test this select call for our socket */
                if (scb->readset && FD_ISSET(s, scb->readset))
                {
                    if (sock->rcvevent > 0)
                    {
                        break;
                    }
                }
                if (scb->writeset && FD_ISSET(s, scb->writeset))
                {
                    if (sock->sendevent)
                    {
                        break;
                    }
                }
            }
        }
        if (scb)
        {
            scb->sem_signalled = 1;
            sys_sem_signal(scb->sem);
            sys_sem_signal(selectsem);
        }
        else
        {
            sys_sem_signal(selectsem);
            break;
        }
    }
}

/**
 * Unimplemented: Close one end of a full-duplex connection.
 * Currently, the full connection is closed.
 */
int
lwip_shutdown(int s, int how)
{
    LWIP_UNUSED_ARG(how);
    LWIP_DEBUGF(SOCKETS_DEBUG, ("lwip_shutdown(%d, how=%d)\n", s, how));
    return lwip_close(s); /* XXX temporary hack until proper implementation */
}

static int
lwip_getaddrname(int s, struct sockaddr *name, socklen_t *namelen, u8_t local)
{
    struct lwip_socket *sock;
    struct sockaddr_in sin;
    struct ip_addr naddr;

    sock = get_socket(s);
    if (!sock)
    {
        return -1;
    }

    memset(&sin, 0, sizeof(sin));
    sin.sin_len = sizeof(sin);
    sin.sin_family = AF_INET;

    /* get the IP address and port */
    netconn_getaddr(sock->conn, &naddr, &sin.sin_port, local);

    LWIP_DEBUGF(SOCKETS_DEBUG, ("lwip_getaddrname(%d, addr=", s));
    ip_addr_debug_print(SOCKETS_DEBUG, &naddr);
    LWIP_DEBUGF(SOCKETS_DEBUG, (" port=%"U 16_F ")\n", sin.sin_port));

    sin.sin_port = htons(sin.sin_port);
    sin.sin_addr.s_addr = naddr.addr;

    if (*namelen > sizeof(sin))
    {
        *namelen = sizeof(sin);
    }

    MEMCPY(name, &sin, *namelen);
    sock_set_errno(sock, 0);
    return 0;
}

int
lwip_getpeername(int s, struct sockaddr *name, socklen_t *namelen)
{
    return lwip_getaddrname(s, name, namelen, 0);
}

int
lwip_getsockname(int s, struct sockaddr *name, socklen_t *namelen)
{
    return lwip_getaddrname(s, name, namelen, 1);
}

int
lwip_getsockopt(int s, int level, int optname, void *optval, socklen_t *optlen)
{
    err_t err = ERR_OK;
    struct lwip_socket *sock = get_socket(s);
    struct lwip_setgetsockopt_data data;

    if (!sock)
    {
        return -1;
    }

    if ((NULL == optval) || (NULL == optlen))
    {
        sock_set_errno(sock, EFAULT);
        return -1;
    }

    /* Do length and type checks for the various options first, to keep it readable. */
    switch (level)
    {

/* Level: SOL_SOCKET */
    case SOL_SOCKET:
        switch (optname)
        {

        case SO_ACCEPTCONN:
        case SO_BROADCAST:
        /* UNIMPL case SO_DEBUG: */
        /* UNIMPL case SO_DONTROUTE: */
        case SO_ERROR:
        case SO_KEEPALIVE:
            /* UNIMPL case SO_CONTIMEO: */
            /* UNIMPL case SO_SNDTIMEO: */
#if LWIP_SO_RCVTIMEO
        case SO_RCVTIMEO:
#endif      /* LWIP_SO_RCVTIMEO */
#if LWIP_SO_RCVBUF
        case SO_RCVBUF:
#endif      /* LWIP_SO_RCVBUF */
            /* UNIMPL case SO_OOBINLINE: */
            /* UNIMPL case SO_SNDBUF: */
            /* UNIMPL case SO_RCVLOWAT: */
            /* UNIMPL case SO_SNDLOWAT: */
#if SO_REUSE
        case SO_REUSEADDR:
        case SO_REUSEPORT:
#endif      /* SO_REUSE */
        case SO_TYPE:
            /* UNIMPL case SO_USELOOPBACK: */
            if (*optlen < sizeof(int))
            {
                err = EINVAL;
            }
            break;

        case SO_NO_CHECK:
            if (*optlen < sizeof(int))
            {
                err = EINVAL;
            }
#if LWIP_UDP
            if ((sock->conn->type != NETCONN_UDP) ||
                ((udp_flags(sock->conn->pcb.udp) & UDP_FLAGS_UDPLITE) != 0))
            {
                /* this flag is only available for UDP, not for UDP lite */
                err = EAFNOSUPPORT;
            }
#endif      /* LWIP_UDP */
            break;

        default:
            LWIP_DEBUGF(SOCKETS_DEBUG, ("lwip_getsockopt(%d, SOL_SOCKET, UNIMPL: optname=0x%x, ..)\n",
                                        s, optname));
            err = ENOPROTOOPT;
        } /* switch (optname) */
        break;

/* Level: IPPROTO_IP */
    case IPPROTO_IP:
        switch (optname)
        {
        /* UNIMPL case IP_HDRINCL: */
        /* UNIMPL case IP_RCVDSTADDR: */
        /* UNIMPL case IP_RCVIF: */
        case IP_TTL:
        case IP_TOS:
            if (*optlen < sizeof(int))
            {
                err = EINVAL;
            }
            break;
#if LWIP_IGMP
        case IP_MULTICAST_TTL:
            if (*optlen < sizeof(u8_t))
            {
                err = EINVAL;
            }
            break;
        case IP_MULTICAST_IF:
            if (*optlen < sizeof(struct in_addr))
            {
                err = EINVAL;
            }
            break;
#endif      /* LWIP_IGMP */

        default:
            LWIP_DEBUGF(SOCKETS_DEBUG, ("lwip_getsockopt(%d, IPPROTO_IP, UNIMPL: optname=0x%x, ..)\n",
                                        s, optname));
            err = ENOPROTOOPT;
        } /* switch (optname) */
        break;

#if LWIP_TCP
/* Level: IPPROTO_TCP */
    case IPPROTO_TCP:
        if (*optlen < sizeof(int))
        {
            err = EINVAL;
            break;
        }

        /* If this is no TCP socket, ignore any options. */
        if (sock->conn->type != NETCONN_TCP)
        {
            return 0;
        }

        switch (optname)
        {
        case TCP_NODELAY:
        case TCP_KEEPALIVE:
#if LWIP_TCP_KEEPALIVE
        case TCP_KEEPIDLE:
        case TCP_KEEPINTVL:
        case TCP_KEEPCNT:
#endif      /* LWIP_TCP_KEEPALIVE */
            break;

        default:
            LWIP_DEBUGF(SOCKETS_DEBUG, ("lwip_getsockopt(%d, IPPROTO_TCP, UNIMPL: optname=0x%x, ..)\n",
                                        s, optname));
            err = ENOPROTOOPT;
        } /* switch (optname) */
        break;
#endif /* LWIP_TCP */
#if LWIP_UDP && LWIP_UDPLITE
/* Level: IPPROTO_UDPLITE */
    case IPPROTO_UDPLITE:
        if (*optlen < sizeof(int))
        {
            err = EINVAL;
            break;
        }

        /* If this is no UDP lite socket, ignore any options. */
        if (sock->conn->type != NETCONN_UDPLITE)
        {
            return 0;
        }

        switch (optname)
        {
        case UDPLITE_SEND_CSCOV:
        case UDPLITE_RECV_CSCOV:
            break;

        default:
            LWIP_DEBUGF(SOCKETS_DEBUG, ("lwip_getsockopt(%d, IPPROTO_UDPLITE, UNIMPL: optname=0x%x, ..)\n",
                                        s, optname));
            err = ENOPROTOOPT;
        } /* switch (optname) */
        break;
#endif /* LWIP_UDP && LWIP_UDPLITE*/
/* UNDEFINED LEVEL */
    default:
        LWIP_DEBUGF(SOCKETS_DEBUG, ("lwip_getsockopt(%d, level=0x%x, UNIMPL: optname=0x%x, ..)\n",
                                    s, level, optname));
        err = ENOPROTOOPT;
    } /* switch */


    if (err != ERR_OK)
    {
        sock_set_errno(sock, err);
        return -1;
    }

    /* Now do the actual option processing */
    data.sock = sock;
    data.level = level;
    data.optname = optname;
    data.optval = optval;
    data.optlen = optlen;
    data.err = err;
    tcpip_callback(lwip_getsockopt_internal, &data);
    sys_arch_sem_wait(sock->conn->op_completed, 0);
    /* maybe lwip_getsockopt_internal has changed err */
    err = data.err;

    sock_set_errno(sock, err);
    return err ? -1 : 0;
}

static void
lwip_getsockopt_internal(void *arg)
{
    struct lwip_socket *sock;

#ifdef LWIP_DEBUG
    int s;
#endif /* LWIP_DEBUG */
    int level, optname;
    void *optval;
    struct lwip_setgetsockopt_data *data;

    LWIP_ASSERT("arg != NULL", arg != NULL);

    data = (struct lwip_setgetsockopt_data*)arg;
    sock = data->sock;
#ifdef LWIP_DEBUG
    s = data->s;
#endif /* LWIP_DEBUG */
    level = data->level;
    optname = data->optname;
    optval = data->optval;

    switch (level)
    {

/* Level: SOL_SOCKET */
    case SOL_SOCKET:
        switch (optname)
        {

        /* The option flags */
        case SO_ACCEPTCONN:
        case SO_BROADCAST:
        /* UNIMPL case SO_DEBUG: */
        /* UNIMPL case SO_DONTROUTE: */
        case SO_KEEPALIVE:
            /* UNIMPL case SO_OOBINCLUDE: */
#if SO_REUSE
        case SO_REUSEADDR:
        case SO_REUSEPORT:
#endif      /* SO_REUSE */
            /*case SO_USELOOPBACK: UNIMPL */
            *(int*)optval = sock->conn->pcb.ip->so_options & optname;
            LWIP_DEBUGF(SOCKETS_DEBUG, ("lwip_getsockopt(%d, SOL_SOCKET, optname=0x%x, ..) = %s\n",
                                        s, optname, (*(int*)optval ? "on" : "off")));
            break;

        case SO_TYPE:
            switch (NETCONNTYPE_GROUP(sock->conn->type))
            {
            case NETCONN_RAW:
                *(int*)optval = SOCK_RAW;
                break;
            case NETCONN_TCP:
                *(int*)optval = SOCK_STREAM;
                break;
            case NETCONN_UDP:
                *(int*)optval = SOCK_DGRAM;
                break;
            default: /* unrecognized socket type */
                *(int*)optval = sock->conn->type;
                LWIP_DEBUGF(SOCKETS_DEBUG,
                            ("lwip_getsockopt(%d, SOL_SOCKET, SO_TYPE): unrecognized socket type %d\n",
                             s, *(int*)optval));
            } /* switch (sock->conn->type) */
            LWIP_DEBUGF(SOCKETS_DEBUG, ("lwip_getsockopt(%d, SOL_SOCKET, SO_TYPE) = %d\n",
                                        s, *(int*)optval));
            break;

        case SO_ERROR:
            if (sock->err == 0)
            {
                sock_set_errno(sock, err_to_errno(sock->conn->err));
            }
            *(int*)optval = sock->err;
            sock->err = 0;
            LWIP_DEBUGF(SOCKETS_DEBUG, ("lwip_getsockopt(%d, SOL_SOCKET, SO_ERROR) = %d\n",
                                        s, *(int*)optval));
            break;

#if LWIP_SO_RCVTIMEO
        case SO_RCVTIMEO:
            *(int*)optval = sock->conn->recv_timeout;
            break;
#endif      /* LWIP_SO_RCVTIMEO */
#if LWIP_SO_RCVBUF
        case SO_RCVBUF:
            *(int*)optval = sock->conn->recv_bufsize;
            break;
#endif      /* LWIP_SO_RCVBUF */
#if LWIP_UDP
        case SO_NO_CHECK:
            *(int*)optval = (udp_flags(sock->conn->pcb.udp) & UDP_FLAGS_NOCHKSUM) ? 1 : 0;
            break;
#endif      /* LWIP_UDP*/
        } /* switch (optname) */
        break;

/* Level: IPPROTO_IP */
    case IPPROTO_IP:
        switch (optname)
        {
        case IP_TTL:
            *(int*)optval = sock->conn->pcb.ip->ttl;
            LWIP_DEBUGF(SOCKETS_DEBUG, ("lwip_getsockopt(%d, IPPROTO_IP, IP_TTL) = %d\n",
                                        s, *(int*)optval));
            break;
        case IP_TOS:
            *(int*)optval = sock->conn->pcb.ip->tos;
            LWIP_DEBUGF(SOCKETS_DEBUG, ("lwip_getsockopt(%d, IPPROTO_IP, IP_TOS) = %d\n",
                                        s, *(int*)optval));
            break;
#if LWIP_IGMP
        case IP_MULTICAST_TTL:
            *(u8_t*)optval = sock->conn->pcb.ip->ttl;
            LWIP_DEBUGF(SOCKETS_DEBUG, ("lwip_getsockopt(%d, IPPROTO_IP, IP_MULTICAST_TTL) = %d\n",
                                        s, *(int*)optval));
            break;
        case IP_MULTICAST_IF:
            ((struct in_addr*)optval)->s_addr = sock->conn->pcb.udp->multicast_ip.addr;
            LWIP_DEBUGF(SOCKETS_DEBUG, ("lwip_getsockopt(%d, IPPROTO_IP, IP_MULTICAST_IF) = 0x%"X 32_F "\n",
                                        s, *(u32_t*)optval));
            break;
#endif      /* LWIP_IGMP */
        } /* switch (optname) */
        break;

#if LWIP_TCP
/* Level: IPPROTO_TCP */
    case IPPROTO_TCP:
        switch (optname)
        {
        case TCP_NODELAY:
            *(int*)optval = tcp_nagle_disabled(sock->conn->pcb.tcp);
            LWIP_DEBUGF(SOCKETS_DEBUG, ("lwip_getsockopt(%d, IPPROTO_TCP, TCP_NODELAY) = %s\n",
                                        s, (*(int*)optval) ? "on" : "off") );
            break;
        case TCP_KEEPALIVE:
            *(int*)optval = (int)sock->conn->pcb.tcp->keep_idle;
            LWIP_DEBUGF(SOCKETS_DEBUG, ("lwip_getsockopt(%d, IPPROTO_IP, TCP_KEEPALIVE) = %d\n",
                                        s, *(int*)optval));
            break;

#if LWIP_TCP_KEEPALIVE
        case TCP_KEEPIDLE:
            *(int*)optval = (int)(sock->conn->pcb.tcp->keep_idle / 1000);
            LWIP_DEBUGF(SOCKETS_DEBUG, ("lwip_getsockopt(%d, IPPROTO_IP, TCP_KEEPIDLE) = %d\n",
                                        s, *(int*)optval));
            break;
        case TCP_KEEPINTVL:
            *(int*)optval = (int)(sock->conn->pcb.tcp->keep_intvl / 1000);
            LWIP_DEBUGF(SOCKETS_DEBUG, ("lwip_getsockopt(%d, IPPROTO_IP, TCP_KEEPINTVL) = %d\n",
                                        s, *(int*)optval));
            break;
        case TCP_KEEPCNT:
            *(int*)optval = (int)sock->conn->pcb.tcp->keep_cnt;
            LWIP_DEBUGF(SOCKETS_DEBUG, ("lwip_getsockopt(%d, IPPROTO_IP, TCP_KEEPCNT) = %d\n",
                                        s, *(int*)optval));
            break;
#endif      /* LWIP_TCP_KEEPALIVE */

        } /* switch (optname) */
        break;
#endif  /* LWIP_TCP */
#if LWIP_UDP && LWIP_UDPLITE
    /* Level: IPPROTO_UDPLITE */
    case IPPROTO_UDPLITE:
        switch (optname)
        {
        case UDPLITE_SEND_CSCOV:
            *(int*)optval = sock->conn->pcb.udp->chksum_len_tx;
            LWIP_DEBUGF(SOCKETS_DEBUG, ("lwip_getsockopt(%d, IPPROTO_UDPLITE, UDPLITE_SEND_CSCOV) = %d\n",
                                        s, (*(int*)optval)) );
            break;
        case UDPLITE_RECV_CSCOV:
            *(int*)optval = sock->conn->pcb.udp->chksum_len_rx;
            LWIP_DEBUGF(SOCKETS_DEBUG, ("lwip_getsockopt(%d, IPPROTO_UDPLITE, UDPLITE_RECV_CSCOV) = %d\n",
                                        s, (*(int*)optval)) );
            break;
        } /* switch (optname) */
        break;
#endif /* LWIP_UDP */
    } /* switch (level) */
    sys_sem_signal(sock->conn->op_completed);
}

int
lwip_setsockopt(int s, int level, int optname, const void *optval, socklen_t optlen)
{
    struct lwip_socket *sock = get_socket(s);
    int err = ERR_OK;
    struct lwip_setgetsockopt_data data;

    if (!sock)
    {
        return -1;
    }

    if (NULL == optval)
    {
        sock_set_errno(sock, EFAULT);
        return -1;
    }

    /* Do length and type checks for the various options first, to keep it readable. */
    switch (level)
    {

/* Level: SOL_SOCKET */
    case SOL_SOCKET:
        switch (optname)
        {

        case SO_BROADCAST:
        /* UNIMPL case SO_DEBUG: */
        /* UNIMPL case SO_DONTROUTE: */
        case SO_KEEPALIVE:
            /* UNIMPL case case SO_CONTIMEO: */
            /* UNIMPL case case SO_SNDTIMEO: */
#if LWIP_SO_RCVTIMEO
        case SO_RCVTIMEO:
#endif      /* LWIP_SO_RCVTIMEO */
#if LWIP_SO_RCVBUF
        case SO_RCVBUF:
#endif      /* LWIP_SO_RCVBUF */
            /* UNIMPL case SO_OOBINLINE: */
            /* UNIMPL case SO_SNDBUF: */
            /* UNIMPL case SO_RCVLOWAT: */
            /* UNIMPL case SO_SNDLOWAT: */
#if SO_REUSE
        case SO_REUSEADDR:
        case SO_REUSEPORT:
#endif      /* SO_REUSE */
            /* UNIMPL case SO_USELOOPBACK: */
            if (optlen < sizeof(int))
            {
                err = EINVAL;
            }
            break;
        case SO_NO_CHECK:
            if (optlen < sizeof(int))
            {
                err = EINVAL;
            }
#if LWIP_UDP
            if ((sock->conn->type != NETCONN_UDP) ||
                ((udp_flags(sock->conn->pcb.udp) & UDP_FLAGS_UDPLITE) != 0))
            {
                /* this flag is only available for UDP, not for UDP lite */
                err = EAFNOSUPPORT;
            }
#endif      /* LWIP_UDP */
            break;
        default:
            LWIP_DEBUGF(SOCKETS_DEBUG, ("lwip_setsockopt(%d, SOL_SOCKET, UNIMPL: optname=0x%x, ..)\n",
                                        s, optname));
            err = ENOPROTOOPT;
        } /* switch (optname) */
        break;

/* Level: IPPROTO_IP */
    case IPPROTO_IP:
        switch (optname)
        {
        /* UNIMPL case IP_HDRINCL: */
        /* UNIMPL case IP_RCVDSTADDR: */
        /* UNIMPL case IP_RCVIF: */
        case IP_TTL:
        case IP_TOS:
            if (optlen < sizeof(int))
            {
                err = EINVAL;
            }
            break;
#if LWIP_IGMP
        case IP_MULTICAST_TTL:
            if (optlen < sizeof(u8_t))
            {
                err = EINVAL;
            }
            if (NETCONNTYPE_GROUP(sock->conn->type) != NETCONN_UDP)
            {
                err = EAFNOSUPPORT;
            }
            break;
        case IP_MULTICAST_IF:
            if (optlen < sizeof(struct in_addr))
            {
                err = EINVAL;
            }
            if (NETCONNTYPE_GROUP(sock->conn->type) != NETCONN_UDP)
            {
                err = EAFNOSUPPORT;
            }
            break;
        case IP_ADD_MEMBERSHIP:
        case IP_DROP_MEMBERSHIP:
            if (optlen < sizeof(struct ip_mreq))
            {
                err = EINVAL;
            }
            if (NETCONNTYPE_GROUP(sock->conn->type) != NETCONN_UDP)
            {
                err = EAFNOSUPPORT;
            }
            break;
#endif      /* LWIP_IGMP */
        default:
            LWIP_DEBUGF(SOCKETS_DEBUG, ("lwip_setsockopt(%d, IPPROTO_IP, UNIMPL: optname=0x%x, ..)\n",
                                        s, optname));
            err = ENOPROTOOPT;
        } /* switch (optname) */
        break;

#if LWIP_TCP
/* Level: IPPROTO_TCP */
    case IPPROTO_TCP:
        if (optlen < sizeof(int))
        {
            err = EINVAL;
            break;
        }

        /* If this is no TCP socket, ignore any options. */
        if (sock->conn->type != NETCONN_TCP)
        {
            return 0;
        }

        switch (optname)
        {
        case TCP_NODELAY:
        case TCP_KEEPALIVE:
#if LWIP_TCP_KEEPALIVE
        case TCP_KEEPIDLE:
        case TCP_KEEPINTVL:
        case TCP_KEEPCNT:
#endif      /* LWIP_TCP_KEEPALIVE */
            break;

        default:
            LWIP_DEBUGF(SOCKETS_DEBUG, ("lwip_setsockopt(%d, IPPROTO_TCP, UNIMPL: optname=0x%x, ..)\n",
                                        s, optname));
            err = ENOPROTOOPT;
        } /* switch (optname) */
        break;
#endif /* LWIP_TCP */
#if LWIP_UDP && LWIP_UDPLITE
/* Level: IPPROTO_UDPLITE */
    case IPPROTO_UDPLITE:
        if (optlen < sizeof(int))
        {
            err = EINVAL;
            break;
        }

        /* If this is no UDP lite socket, ignore any options. */
        if (sock->conn->type != NETCONN_UDPLITE)
        {
            return 0;
        }

        switch (optname)
        {
        case UDPLITE_SEND_CSCOV:
        case UDPLITE_RECV_CSCOV:
            break;

        default:
            LWIP_DEBUGF(SOCKETS_DEBUG, ("lwip_setsockopt(%d, IPPROTO_UDPLITE, UNIMPL: optname=0x%x, ..)\n",
                                        s, optname));
            err = ENOPROTOOPT;
        } /* switch (optname) */
        break;
#endif /* LWIP_UDP && LWIP_UDPLITE */
/* UNDEFINED LEVEL */
    default:
        LWIP_DEBUGF(SOCKETS_DEBUG, ("lwip_setsockopt(%d, level=0x%x, UNIMPL: optname=0x%x, ..)\n",
                                    s, level, optname));
        err = ENOPROTOOPT;
    } /* switch (level) */


    if (err != ERR_OK)
    {
        sock_set_errno(sock, err);
        return -1;
    }


    /* Now do the actual option processing */
    data.sock = sock;
    data.level = level;
    data.optname = optname;
    data.optval = (void*)optval;
    data.optlen = &optlen;
    data.err = err;
    tcpip_callback(lwip_setsockopt_internal, &data);
    sys_arch_sem_wait(sock->conn->op_completed, 0);
    /* maybe lwip_setsockopt_internal has changed err */
    err = data.err;

    sock_set_errno(sock, err);
    return err ? -1 : 0;
}

static void
lwip_setsockopt_internal(void *arg)
{
    struct lwip_socket *sock;

#ifdef LWIP_DEBUG
    int s;
#endif /* LWIP_DEBUG */
    int level, optname;
    const void *optval;
    struct lwip_setgetsockopt_data *data;

    LWIP_ASSERT("arg != NULL", arg != NULL);

    data = (struct lwip_setgetsockopt_data*)arg;
    sock = data->sock;
#ifdef LWIP_DEBUG
    s = data->s;
#endif /* LWIP_DEBUG */
    level = data->level;
    optname = data->optname;
    optval = data->optval;

    switch (level)
    {

/* Level: SOL_SOCKET */
    case SOL_SOCKET:
        switch (optname)
        {

        /* The option flags */
        case SO_BROADCAST:
        /* UNIMPL case SO_DEBUG: */
        /* UNIMPL case SO_DONTROUTE: */
        case SO_KEEPALIVE:
            /* UNIMPL case SO_OOBINCLUDE: */
#if SO_REUSE
        case SO_REUSEADDR:
        case SO_REUSEPORT:
#endif      /* SO_REUSE */
            /* UNIMPL case SO_USELOOPBACK: */
            if (*(int*)optval)
            {
                sock->conn->pcb.ip->so_options |= optname;
            }
            else
            {
                sock->conn->pcb.ip->so_options &= ~optname;
            }
            LWIP_DEBUGF(SOCKETS_DEBUG, ("lwip_setsockopt(%d, SOL_SOCKET, optname=0x%x, ..) -> %s\n",
                                        s, optname, (*(int*)optval ? "on" : "off")));
            break;
#if LWIP_SO_RCVTIMEO
        case SO_RCVTIMEO:
            sock->conn->recv_timeout = ( *(int*)optval );
            break;
#endif      /* LWIP_SO_RCVTIMEO */
#if LWIP_SO_RCVBUF
        case SO_RCVBUF:
            sock->conn->recv_bufsize = ( *(int*)optval );
            break;
#endif      /* LWIP_SO_RCVBUF */
#if LWIP_UDP
        case SO_NO_CHECK:
            if (*(int*)optval)
            {
                udp_setflags(sock->conn->pcb.udp, udp_flags(sock->conn->pcb.udp) | UDP_FLAGS_NOCHKSUM);
            }
            else
            {
                udp_setflags(sock->conn->pcb.udp, udp_flags(sock->conn->pcb.udp) & ~UDP_FLAGS_NOCHKSUM);
            }
            break;
#endif      /* LWIP_UDP */
        } /* switch (optname) */
        break;

/* Level: IPPROTO_IP */
    case IPPROTO_IP:
        switch (optname)
        {
        case IP_TTL:
            sock->conn->pcb.ip->ttl = (u8_t)(*(int*)optval);
            LWIP_DEBUGF(SOCKETS_DEBUG, ("lwip_setsockopt(%d, IPPROTO_IP, IP_TTL, ..) -> %d\n",
                                        s, sock->conn->pcb.ip->ttl));
            break;
        case IP_TOS:
            sock->conn->pcb.ip->tos = (u8_t)(*(int*)optval);
            LWIP_DEBUGF(SOCKETS_DEBUG, ("lwip_setsockopt(%d, IPPROTO_IP, IP_TOS, ..)-> %d\n",
                                        s, sock->conn->pcb.ip->tos));
            break;
#if LWIP_IGMP
        case IP_MULTICAST_TTL:
            sock->conn->pcb.udp->ttl = (u8_t)(*(u8_t*)optval);
            break;
        case IP_MULTICAST_IF:
            sock->conn->pcb.udp->multicast_ip.addr = ((struct in_addr*)optval)->s_addr;
            break;
        case IP_ADD_MEMBERSHIP:
        case IP_DROP_MEMBERSHIP:
        {
            /* If this is a TCP or a RAW socket, ignore these options. */
            struct ip_mreq *imr = (struct ip_mreq*)optval;
            if (optname == IP_ADD_MEMBERSHIP)
            {
                data->err = igmp_joingroup((struct ip_addr*)&(imr->imr_interface.s_addr), (struct ip_addr*)&(imr->imr_multiaddr.s_addr));
            }
            else
            {
                data->err = igmp_leavegroup((struct ip_addr*)&(imr->imr_interface.s_addr), (struct ip_addr*)&(imr->imr_multiaddr.s_addr));
            }
            if (data->err != ERR_OK)
            {
                data->err = EADDRNOTAVAIL;
            }
        }
        break;
#endif      /* LWIP_IGMP */
        } /* switch (optname) */
        break;

#if LWIP_TCP
/* Level: IPPROTO_TCP */
    case IPPROTO_TCP:
        switch (optname)
        {
        case TCP_NODELAY:
            if (*(int*)optval)
            {
                tcp_nagle_disable(sock->conn->pcb.tcp);
            }
            else
            {
                tcp_nagle_enable(sock->conn->pcb.tcp);
            }
            LWIP_DEBUGF(SOCKETS_DEBUG, ("lwip_setsockopt(%d, IPPROTO_TCP, TCP_NODELAY) -> %s\n",
                                        s, (*(int*)optval) ? "on" : "off") );
            break;
        case TCP_KEEPALIVE:
            sock->conn->pcb.tcp->keep_idle = (u32_t)(*(int*)optval);
            LWIP_DEBUGF(SOCKETS_DEBUG, ("lwip_setsockopt(%d, IPPROTO_TCP, TCP_KEEPALIVE) -> %"U 32_F "\n",
                                        s, sock->conn->pcb.tcp->keep_idle));
            break;

#if LWIP_TCP_KEEPALIVE
        case TCP_KEEPIDLE:
            sock->conn->pcb.tcp->keep_idle = 1000 * (u32_t)(*(int*)optval);
            LWIP_DEBUGF(SOCKETS_DEBUG, ("lwip_setsockopt(%d, IPPROTO_TCP, TCP_KEEPIDLE) -> %"U 32_F "\n",
                                        s, sock->conn->pcb.tcp->keep_idle));
            break;
        case TCP_KEEPINTVL:
            sock->conn->pcb.tcp->keep_intvl = 1000 * (u32_t)(*(int*)optval);
            LWIP_DEBUGF(SOCKETS_DEBUG, ("lwip_setsockopt(%d, IPPROTO_TCP, TCP_KEEPINTVL) -> %"U 32_F "\n",
                                        s, sock->conn->pcb.tcp->keep_intvl));
            break;
        case TCP_KEEPCNT:
            sock->conn->pcb.tcp->keep_cnt = (u32_t)(*(int*)optval);
            LWIP_DEBUGF(SOCKETS_DEBUG, ("lwip_setsockopt(%d, IPPROTO_TCP, TCP_KEEPCNT) -> %"U 32_F "\n",
                                        s, sock->conn->pcb.tcp->keep_cnt));
            break;
#endif      /* LWIP_TCP_KEEPALIVE */

        } /* switch (optname) */
        break;
#endif  /* LWIP_TCP*/
#if LWIP_UDP && LWIP_UDPLITE
    /* Level: IPPROTO_UDPLITE */
    case IPPROTO_UDPLITE:
        switch (optname)
        {
        case UDPLITE_SEND_CSCOV:
            if ((*(int*)optval != 0) && (*(int*)optval < 8))
            {
                /* don't allow illegal values! */
                sock->conn->pcb.udp->chksum_len_tx = 8;
            }
            else
            {
                sock->conn->pcb.udp->chksum_len_tx = *(int*)optval;
            }
            LWIP_DEBUGF(SOCKETS_DEBUG, ("lwip_setsockopt(%d, IPPROTO_UDPLITE, UDPLITE_SEND_CSCOV) -> %d\n",
                                        s, (*(int*)optval)) );
            break;
        case UDPLITE_RECV_CSCOV:
            if ((*(int*)optval != 0) && (*(int*)optval < 8))
            {
                /* don't allow illegal values! */
                sock->conn->pcb.udp->chksum_len_rx = 8;
            }
            else
            {
                sock->conn->pcb.udp->chksum_len_rx = *(int*)optval;
            }
            LWIP_DEBUGF(SOCKETS_DEBUG, ("lwip_setsockopt(%d, IPPROTO_UDPLITE, UDPLITE_RECV_CSCOV) -> %d\n",
                                        s, (*(int*)optval)) );
            break;
        } /* switch (optname) */
        break;
#endif /* LWIP_UDP */
    } /* switch (level) */
    sys_sem_signal(sock->conn->op_completed);
}

int
lwip_ioctl(int s, long cmd, void *argp)
{
    struct lwip_socket *sock = get_socket(s);
    u16_t buflen = 0;
    s16_t recv_avail;

    if (!sock)
    {
        return -1;
    }

    switch (cmd)
    {
    case FIONREAD:
        if (!argp)
        {
            sock_set_errno(sock, EINVAL);
            return -1;
        }

        SYS_ARCH_GET(sock->conn->recv_avail, recv_avail);
        if (recv_avail < 0)
        {
            recv_avail = 0;
        }
        *((u16_t*)argp) = (u16_t)recv_avail;

        /* Check if there is data left from the last recv operation. /maq 041215 */
        if (sock->lastdata)
        {
            buflen = netbuf_len(sock->lastdata);
            buflen -= sock->lastoffset;

            *((u16_t*)argp) += buflen;
        }

        LWIP_DEBUGF(SOCKETS_DEBUG, ("lwip_ioctl(%d, FIONREAD, %p) = %"U 16_F "\n", s, argp, *((u16_t*)argp)));
        sock_set_errno(sock, 0);
        return 0;

    case FIONBIO:
        if (argp && *(u32_t*)argp)
        {
            sock->flags |= O_NONBLOCK;
        }
        else
        {
            sock->flags &= ~O_NONBLOCK;
        }
        LWIP_DEBUGF(SOCKETS_DEBUG, ("lwip_ioctl(%d, FIONBIO, %d)\n", s, !!(sock->flags & O_NONBLOCK)));
        sock_set_errno(sock, 0);
        return 0;

    default:
        LWIP_DEBUGF(SOCKETS_DEBUG, ("lwip_ioctl(%d, UNIMPL: 0x%lx, %p)\n", s, cmd, argp));
        sock_set_errno(sock, ENOSYS); /* not yet implemented */
        return -1;
    } /* switch (cmd) */
}

#endif /* LWIP_SOCKET */
